Harmonic balance algorithm to model nonlinear effects in HTS filters subject to CDMA signals

We discuss an harmonic balance algorithm to analyze High Temperature Superconducting (HTS) circuits subject to wideband signals, such as the ones used in CDMA wireless systems. Undersampling is used to discretize and down-convert the bandpass signal resulting from the weak HTS nonlinearities, and this has to be taken into account when performing time-domain calculations of the nonlinear effects. We present an overview of the algorithm and describe an example to verify the software developed. We also discuss a tentative performance assessment of an HTS preselect filter in a UMTS base station receiver.